1. Technical Field
The present invention relates to a liquid crystal display, a method for producing a liquid crystal display, and an electronic apparatus.
2. Related Art
To achieve a wider viewing angle of a liquid crystal display, the use of a mode of controlling the alignment of liquid crystal molecules by generating an electric field in a direction parallel to a substrate and applying the electric field to a liquid crystal layer (hereinafter, referred to as a “lateral electric field mode”) has been known. Known examples of such a lateral electric field mode include an in-plane switching (IPS) mode and a fringe-field switching (FFS) mode (for example, see JP A 2005-338256).
In a liquid crystal display operating in such a lateral electric field mode, a pixel electrode and a common electrode, which are a pair of electrodes for driving liquid crystal molecules, are arranged on one of a pair of substrates holding a liquid crystal layer with an electrode insulating film provided therebetween. In general, one electrode arranged below the electrode insulating film is disposed on a resin film such as an acrylic resin film. In a transflective liquid crystal display, a reflective film composed of aluminum (Al) is arranged on the resin film and the one electrode is arranged on the reflective film and the resin film.
To suppress the effect of the electric field between adjoining pixel regions, in some cases, a pixel electrode connected to a driving element such as a TFT element is disposed further apart from the liquid crystal layer than the common electrode. This is because if the pixel electrode is located closer to the liquid crystal layer side than the common electrode, an electric filed generated in a pixel region expands to adjacent pixel regions through the liquid crystal layer to affect peripheries of adjacent pixel regions.
JP A 2005-338256 is an example of related art.
However, the above-described known liquid crystal display has the following problems. That is, in the known liquid crystal display the one electrode is disposed on the resin film composed of acrylic, which is an organic oxide. To inhibit damage from an oxygen-containing gas to the resin film, the electrode insulating film is preferably composed of silicon nitride (SiN), which is a material that does not require a large amount of an oxygen-containing gas. However, the use of the electrode insulating film composed of SiN causes image sticking because SiN has electronic defect levels (traps) and a large charge-storing effect. Thus, formation of an additional insulating film composed of SiN on the resin film and an electrode insulating film composed of SiO2 having a small number of defect levels has been proposed. In this case, to connect the pixel electrode with the driving element, a through hole passing through the additional insulating film needs to be formed. Therefore, a step of forming the through hole passing through only the additional insulating film is separately required in addition to a step of forming the additional insulating film. This disadvantageously results in a complex production process.
In the case where the one electrode is formed on the reflective film composed of Al, an ITO film constituting the one electrode is formed so as to cover the reflective film, and is then patterned. However, a contact potential is generated between ITO and Al; hence, Al is etched when being immersed in an electrolytic solution. Thus, it is proposed that an additional insulating film is formed so as to cover the reflective film to insulate the reflective film from the one electrode. However, a through hole passing through the additional insulating film needs to be formed in order to connect the pixel electrode to the driving element in the same way as described above. Therefore, a step of forming the through hole passing through only the additional insulating film is separately required in addition to a step of forming the additional insulating film. This disadvantageously results in a complex production process.